Electric water heater only heat the water you use. They just need a cold water supply and are ready to go without you having to heat the water first – meaning you don’t have to wait ages for a water tank to heat up before you can shower. And because they heat a minimal amount of water they'll help you save on your energy bills.

Electric water heater heat water inside the shower unit; water doesn't come into contact with your boiler. This means that if your boiler's on the blink you'll still be able to have a hot shower.

How powerful are electric showers?

Electric showers have a weaker flow than mixer showers or power showers. If you’re after a shower that delivers cascades of hot water to your morning shower, an electric model is unlikely to measure up. Electric shower power levels range from 5kW to around 16kW. In general, the higher the wattage the more water can be heated and passed through the shower head in one go and the faster you’ll be able to wash the shampoo from your hair.

We’ve tested a range of the latest electric showers from big brands such as Aqualisa, Mira and Triton, including a range from 5kW to 16kW. To see which topped our tests, check out our electric shower reviews. Who are electric showers suitable for? Anyone can have an electric shower installed, as they run off cold mains water and aren’t affected by the type of water system you have in your home. This can make them suitable for unheated rooms or buildings with storage heaters, such as an outhouse or converted garage.